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1\section{\class{wxArray}}\label{wxarray}
2
3This section describes the so called {\it dynamic arrays}. This is a C
4array-like data structure i.e. the member access time is constant (and not
5linear according to the number of container elements as for linked lists). However, these
6arrays are dynamic in the sense that they will automatically allocate more
7memory if there is not enough of it for adding a new element. They also perform
8range checking on the index values but in debug mode only, so please be sure to
9compile your application in debug mode to use it (see \helpref{debugging overview}{debuggingoverview} for
10details). So, unlike the arrays in some other
11languages, attempt to access an element beyond the arrays bound doesn't
12automatically expand the array but provokes an assertion failure instead in
13debug build and does nothing (except possibly crashing your program) in the
14release build.
15
16The array classes were designed to be reasonably efficient, both in terms of
17run-time speed and memory consumption and the executable size. The speed of
18array item access is, of course, constant (independent of the number of elements)
19making them much more efficient than linked lists (\helpref{wxList}{wxlist}).
20Adding items to the arrays is also implemented in more or less constant time -
21but the price is preallocating the memory in advance. In the \helpref{memory management}{wxarraymemorymanagement} section
22you may find some useful hints about optimizing wxArray memory usage. As for executable size, all
23wxArray functions are inline, so they do not take {\it any space at all}.
24
25wxWindows has three different kinds of array. All of them derive from
26wxBaseArray class which works with untyped data and can not be used directly.
27The standard macros WX\_DEFINE\_ARRAY(), WX\_DEFINE\_SORTED\_ARRAY() and
28WX\_DEFINE\_OBJARRAY() are used to define a new class deriving from it. The
29classes declared will be called in this documentation wxArray, wxSortedArray and
30wxObjArray but you should keep in mind that no classes with such names actually
31exist, each time you use one of WX\_DEFINE\_XXXARRAY macro you define a class
32with a new name. In fact, these names are "template" names and each usage of one
33of the macros mentioned above creates a template specialization for the given
34element type.
35
36wxArray is suitable for storing integer types and pointers which it does not
37treat as objects in any way, i.e. the element pointed to by the pointer is not
38deleted when the element is removed from the array. It should be noted that
39all of wxArray's functions are inline, so it costs strictly nothing to define as
40many array types as you want (either in terms of the executable size or the
41speed) as long as at least one of them is defined and this is always the case
42because wxArrays are used by wxWindows internally. This class has one serious
43limitation: it can only be used for storing integral types (bool, char, short,
44int, long and their unsigned variants) or pointers (of any kind). An attempt
45to use with objects of sizeof() greater than sizeof(long) will provoke a
46runtime assertion failure, however declaring a wxArray of floats will not (on
47the machines where sizeof(float) <= sizeof(long)), yet it will {\bf not} work,
48please use wxObjArray for storing floats and doubles (NB: a more efficient
49wxArrayDouble class is scheduled for the next release of wxWindows).
50
51wxSortedArray is a wxArray variant which should be used when searching in the
52array is a frequently used operation. It requires you to define an additional
53function for comparing two elements of the array element type and always stores
54its items in the sorted order (according to this function). Thus, it is
55 \helpref{Index()}{wxarrayindex} function execution time is $O(log(N))$ instead of
56$O(N)$ for the usual arrays but the \helpref{Add()}{wxarrayadd} method is
57slower: it is $O(log(N))$ instead of constant time (neglecting time spent in
58memory allocation routine). However, in a usual situation elements are added to
59an array much less often than searched inside it, so wxSortedArray may lead to
60huge performance improvements compared to wxArray. Finally, it should be
61noticed that, as wxArray, wxSortedArray can be only used for storing integral
62types or pointers.
63
64wxObjArray class treats its elements like "objects". It may delete them when
65they are removed from the array (invoking the correct destructor) and copies
66them using the objects copy constructor. In order to implement this behaviour
67the definition of the wxObjArray arrays is split in two parts: first, you should
68declare the new wxObjArray class using WX\_DECLARE\_OBJARRAY() macro and then
69you must include the file defining the implementation of template type:
70<wx/arrimpl.cpp> and define the array class with WX\_DEFINE\_OBJARRAY() macro
71from a point where the full (as opposed to `forward') declaration of the array
72elements class is in scope. As it probably sounds very complicated here is an
73example:
74
75\begin{verbatim}
76#include <wx/dynarray.h>
77
78// we must forward declare the array because it is used inside the class
79// declaration
80class MyDirectory;
81class MyFile;
82
83// this defines two new types: ArrayOfDirectories and ArrayOfFiles which can be
84// now used as shown below
85WX_DECLARE_OBJARRAY(MyDirectory, ArrayOfDirectories);
86WX_DECLARE_OBJARRAY(MyFile, ArrayOfFiles);
87
88class MyDirectory
89{
90...
91 ArrayOfDirectories m_subdirectories; // all subdirectories
92 ArrayOfFiles m_files; // all files in this directory
93};
94
95...
96
97// now that we have MyDirectory declaration in scope we may finish the
98// definition of ArrayOfDirectories -- note that this expands into some C++
99// code and so should only be compiled once (i.e., don't put this in the
100// header, but into a source file or you will get linking errors)
101#include <wx/arrimpl.cpp> // this is a magic incantation which must be done!
102WX_DEFINE_OBJARRAY(ArrayOfDirectories);
103
104// that's all!
105\end{verbatim}
106
107It is not as elegant as writing
108
109\begin{verbatim}
110typedef std::vector<MyDirectory> ArrayOfDirectories;
111\end{verbatim}
112
113but is not that complicated and allows the code to be compiled with any, however
114dumb, C++ compiler in the world.
115
116Things are much simpler for wxArray and wxSortedArray however: it is enough
117just to write
118
119\begin{verbatim}
120WX_DEFINE_ARRAY(MyDirectory *, ArrayOfDirectories);
121WX_DEFINE_SORTED_ARRAY(MyFile *, ArrayOfFiles);
122\end{verbatim}
123
124\wxheading{See also:}
125
126\helpref{Container classes overview}{wxcontaineroverview}, \helpref{wxList}{wxlist}
127
128\wxheading{Include files}
129
130<wx/dynarray.h> for wxArray and wxSortedArray and additionally <wx/arrimpl.cpp>
131for wxObjArray.
132
133\latexignore{\rtfignore{\wxheading{Function groups}}}
134
135\membersection{Macros for template array definition}
136
137To use an array you must first define the array class. This is done with the
138help of the macros in this section. The class of array elements must be (at
139least) forward declared for WX\_DEFINE\_ARRAY, WX\_DEFINE\_SORTED\_ARRAY and
140WX\_DECLARE\_OBJARRAY macros and must be fully declared before you use
141WX\_DEFINE\_OBJARRAY macro.
142
143\helpref{WX\_DEFINE\_ARRAY}{wxdefinearray}\\
144\helpref{WX\_DEFINE\_EXPORTED\_ARRAY}{wxdefinearray}\\
145\helpref{WX\_DEFINE\_USER\_EXPORTED\_ARRAY}{wxdefinearray}\\
146\helpref{WX\_DEFINE\_SORTED\_ARRAY}{wxdefinesortedarray}\\
147\helpref{WX\_DEFINE\_SORTED\_EXPORTED\_ARRAY}{wxdefinesortedarray}\\
148\helpref{WX\_DEFINE\_SORTED\_USER\_EXPORTED\_ARRAY}{wxdefinesortedarray}\\
149\helpref{WX\_DECLARE\_EXPORTED\_OBJARRAY}{wxdeclareobjarray}\\
150\helpref{WX\_DECLARE\_USER\_EXPORTED\_OBJARRAY}{wxdeclareobjarray}\\
151\helpref{WX\_DEFINE\_OBJARRAY}{wxdefineobjarray}\\
152\helpref{WX\_DEFINE\_EXPORTED\_OBJARRAY}{wxdefineobjarray}\\
153\helpref{WX\_DEFINE\_USER\_EXPORTED\_OBJARRAY}{wxdefineobjarray}
154
155\membersection{Constructors and destructors}
156
157Array classes are 100\% C++ objects and as such they have the appropriate copy
158constructors and assignment operators. Copying wxArray just copies the elements
159but copying wxObjArray copies the arrays items. However, for memory-efficiency
160sake, neither of these classes has virtual destructor. It is not very important
161for wxArray which has trivial destructor anyhow, but it does mean that you
162should avoid deleting wxObjArray through a wxBaseArray pointer (as you would
163never use wxBaseArray anyhow it shouldn't be a problem) and that you should not
164derive your own classes from the array classes.
165
166\helpref{wxArray default constructor}{wxarrayctordef}\\
167\helpref{wxArray copy constructors and assignment operators}{wxarrayctorcopy}\\
168\helpref{\destruct{wxArray}}{wxarraydtor}
169
170\membersection{Memory management}\label{wxarraymemorymanagement}
171
172Automatic array memory management is quite trivial: the array starts by
173preallocating some minimal amount of memory (defined by
174WX\_ARRAY\_DEFAULT\_INITIAL\_SIZE) and when further new items exhaust already
175allocated memory it reallocates it adding 50\% of the currently allocated
176amount, but no more than some maximal number which is defined by
177ARRAY\_MAXSIZE\_INCREMENT constant. Of course, this may lead to some memory
178being wasted (ARRAY\_MAXSIZE\_INCREMENT in the worst case, i.e. 4Kb in the
179current implementation), so the \helpref{Shrink()}{wxarrayshrink} function is
180provided to deallocate the extra memory. The \helpref{Alloc()}{wxarrayalloc}
181function can also be quite useful if you know in advance how many items you are
182going to put in the array and will prevent the array code from reallocating the
183memory more times than needed.
184
185\helpref{Alloc}{wxarrayalloc}\\
186\helpref{Shrink}{wxarrayshrink}
187
188\membersection{Number of elements and simple item access}
189
190Functions in this section return the total number of array elements and allow to
191retrieve them - possibly using just the C array indexing $[]$ operator which
192does exactly the same as \helpref{Item()}{wxarrayitem} method.
193
194\helpref{Count}{wxarraycount}\\
195\helpref{GetCount}{wxarraygetcount}\\
196\helpref{IsEmpty}{wxarrayisempty}\\
197\helpref{Item}{wxarrayitem}\\
198\helpref{Last}{wxarraylast}
199
200\membersection{Adding items}
201
202\helpref{Add}{wxarrayadd}\\
203\helpref{Insert}{wxarrayinsert}\\
204\helpref{SetCount}{wxarraysetcount}\\
205\helpref{WX\_APPEND\_ARRAY}{wxappendarray}
206
207\membersection{Removing items}
208
209\helpref{WX\_CLEAR\_ARRAY}{wxcleararray}\\
210\helpref{Empty}{wxarrayempty}\\
211\helpref{Clear}{wxarrayclear}\\
212\helpref{RemoveAt}{wxarrayremoveat}\\
213\helpref{Remove}{wxarrayremove}
214
215\membersection{Searching and sorting}
216
217\helpref{Index}{wxarrayindex}\\
218\helpref{Sort}{wxarraysort}
219
220%%%%% MEMBERS HERE %%%%%
221\helponly{\insertatlevel{2}{
222
223\wxheading{Members}
224
225}}
226
227\membersection{WX\_DEFINE\_ARRAY}\label{wxdefinearray}
228
229\func{}{WX\_DEFINE\_ARRAY}{\param{}{T}, \param{}{name}}
230
231\func{}{WX\_DEFINE\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}}
232
233\func{}{WX\_DEFINE\_USER\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}, \param{}{exportspec}}
234
235This macro defines a new array class named {\it name} and containing the
236elements of type {\it T}. The second form is used when compiling wxWindows as
237a DLL under Windows and array needs to be visible outside the DLL. The third is
238needed for exporting an array from a user DLL.
239
240Example:
241
242\begin{verbatim}
243WX_DEFINE_ARRAY(int, wxArrayInt);
244
245class MyClass;
246WX_DEFINE_ARRAY(MyClass *, wxArrayOfMyClass);
247\end{verbatim}
248
249Note that wxWindows predefines the following standard array classes: wxArrayInt,
250wxArrayLong and wxArrayPtrVoid.
251
252\membersection{WX\_DEFINE\_SORTED\_ARRAY}\label{wxdefinesortedarray}
253
254\func{}{WX\_DEFINE\_SORTED\_ARRAY}{\param{}{T}, \param{}{name}}
255
256\func{}{WX\_DEFINE\_SORTED\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}}
257
258\func{}{WX\_DEFINE\_SORTED\_USER\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}}
259
260This macro defines a new sorted array class named {\it name} and containing
261the elements of type {\it T}. The second form is used when compiling wxWindows as
262a DLL under Windows and array needs to be visible outside the DLL. The third is
263needed for exporting an array from a user DLL.
264
265Example:
266
267\begin{verbatim}
268WX_DEFINE_SORTED_ARRAY(int, wxSortedArrayInt);
269
270class MyClass;
271WX_DEFINE_SORTED_ARRAY(MyClass *, wxArrayOfMyClass);
272\end{verbatim}
273
274You will have to initialize the objects of this class by passing a comparison
275function to the array object constructor like this:
276
277\begin{verbatim}
278int CompareInts(int n1, int n2)
279{
280 return n1 - n2;
281}
282
283wxSortedArrayInt sorted(CompareInts);
284
285int CompareMyClassObjects(MyClass *item1, MyClass *item2)
286{
287 // sort the items by their address...
288 return Stricmp(item1->GetAddress(), item2->GetAddress());
289}
290
291wxArrayOfMyClass another(CompareMyClassObjects);
292\end{verbatim}
293
294\membersection{WX\_DECLARE\_OBJARRAY}\label{wxdeclareobjarray}
295
296\func{}{WX\_DECLARE\_OBJARRAY}{\param{}{T}, \param{}{name}}
297
298\func{}{WX\_DECLARE\_EXPORTED\_OBJARRAY}{\param{}{T}, \param{}{name}}
299
300\func{}{WX\_DECLARE\_USER\_EXPORTED\_OBJARRAY}{\param{}{T}, \param{}{name}}
301
302This macro declares a new object array class named {\it name} and containing
303the elements of type {\it T}. The second form is used when compiling wxWindows as
304a DLL under Windows and array needs to be visible outside the DLL. The third is
305needed for exporting an array from a user DLL.
306
307Example:
308
309\begin{verbatim}
310class MyClass;
311WX_DECLARE_OBJARRAY(MyClass, wxArrayOfMyClass); // note: not "MyClass *"!
312\end{verbatim}
313
314You must use \helpref{WX\_DEFINE\_OBJARRAY()}{wxdefineobjarray} macro to define
315the array class - otherwise you would get link errors.
316
317\membersection{WX\_DEFINE\_OBJARRAY}\label{wxdefineobjarray}
318
319\func{}{WX\_DEFINE\_OBJARRAY}{\param{}{name}}
320
321\func{}{WX\_DEFINE\_EXPORTED\_OBJARRAY}{\param{}{name}}
322
323\func{}{WX\_DEFINE\_USER\_EXPORTED\_OBJARRAY}{\param{}{name}}
324
325This macro defines the methods of the array class {\it name} not defined by the
326\helpref{WX\_DECLARE\_OBJARRAY()}{wxdeclareobjarray} macro. You must include the
327file <wx/arrimpl.cpp> before using this macro and you must have the full
328declaration of the class of array elements in scope! If you forget to do the
329first, the error will be caught by the compiler, but, unfortunately, many
330compilers will not give any warnings if you forget to do the second - but the
331objects of the class will not be copied correctly and their real destructor will
332not be called. The latter two forms are merely aliases of the first to satisfy
333some people's sense of symmetry when using the exported declarations.
334
335Example of usage:
336
337\begin{verbatim}
338// first declare the class!
339class MyClass
340{
341public:
342 MyClass(const MyClass&);
343
344 ...
345
346 virtual ~MyClass();
347};
348
349#include <wx/arrimpl.cpp>
350WX_DEFINE_OBJARRAY(wxArrayOfMyClass);
351\end{verbatim}
352
353\membersection{WX\_APPEND\_ARRAY}\label{wxappendarray}
354
355\func{void}{WX\_APPEND\_ARRAY}{\param{wxArray\& }{array}, \param{wxArray\& }{other}}
356
357This macro may be used to append all elements of the {\it other} array to the
358{\it array}. The two arrays must be of the same type.
359
360\membersection{WX\_CLEAR\_ARRAY}\label{wxcleararray}
361
362\func{void}{WX\_CLEAR\_ARRAY}{\param{wxArray\& }{array}}
363
364This macro may be used to delete all elements of the array before emptying it.
365It can not be used with wxObjArrays - but they will delete their elements anyhow
366when you call Empty().
367
368\membersection{Default constructors}\label{wxarrayctordef}
369
370\func{}{wxArray}{\void}
371
372\func{}{wxObjArray}{\void}
373
374Default constructor initializes an empty array object.
375
376\func{}{wxSortedArray}{\param{int (*)(T first, T second)}{compareFunction}}
377
378There is no default constructor for wxSortedArray classes - you must initialize it
379with a function to use for item comparison. It is a function which is passed
380two arguments of type {\it T} where {\it T} is the array element type and which
381should return a negative, zero or positive value according to whether the first
382element passed to it is less than, equal to or greater than the second one.
383
384\membersection{wxArray copy constructor and assignment operator}\label{wxarrayctorcopy}
385
386\func{}{wxArray}{\param{const wxArray\& }{array}}
387
388\func{}{wxSortedArray}{\param{const wxSortedArray\& }{array}}
389
390\func{}{wxObjArray}{\param{const wxObjArray\& }{array}}
391
392\func{wxArray\&}{operator$=$}{\param{const wxArray\& }{array}}
393
394\func{wxSortedArray\&}{operator$=$}{\param{const wxSortedArray\& }{array}}
395
396\func{wxObjArray\&}{operator$=$}{\param{const wxObjArray\& }{array}}
397
398The copy constructors and assignment operators perform a shallow array copy
399(i.e. they don't copy the objects pointed to even if the source array contains
400the items of pointer type) for wxArray and wxSortedArray and a deep copy (i.e.
401the array element are copied too) for wxObjArray.
402
403\membersection{wxArray::\destruct{wxArray}}\label{wxarraydtor}
404
405\func{}{\destruct{wxArray}}{\void}
406
407\func{}{\destruct{wxSortedArray}}{\void}
408
409\func{}{\destruct{wxObjArray}}{\void}
410
411The wxObjArray destructor deletes all the items owned by the array. This is not
412done by wxArray and wxSortedArray versions - you may use
413\helpref{WX\_CLEAR\_ARRAY}{wxcleararray} macro for this.
414
415\membersection{wxArray::Add}\label{wxarrayadd}
416
417\func{void}{Add}{\param{T }{item}, \param{size\_t}{ copies = $1$}}
418
419\func{void}{Add}{\param{T *}{item}}
420
421\func{void}{Add}{\param{T \&}{item}, \param{size\_t}{ copies = $1$}}
422
423Appends the given number of {\it copies} of the {\it item} to the array
424consisting of the elements of type {\it T}.
425
426The first version is used with wxArray and wxSortedArray. The second and the
427third are used with wxObjArray. There is an important difference between
428them: if you give a pointer to the array, it will take ownership of it, i.e.
429will delete it when the item is deleted from the array. If you give a reference
430to the array, however, the array will make a copy of the item and will not take
431ownership of the original item. Once again, it only makes sense for wxObjArrays
432because the other array types never take ownership of their elements. Also note
433that you cannot append more than one pointer as reusing it would lead to
434deleting it twice (or more) and hence to a crash.
435
436You may also use \helpref{WX\_APPEND\_ARRAY}{wxappendarray} macro to append all
437elements of one array to another one but it is more efficient to use
438{\it copies} parameter and modify the elements in place later if you plan to
439append a lot of items.
440
441\membersection{wxArray::Alloc}\label{wxarrayalloc}
442
443\func{void}{Alloc}{\param{size\_t }{count}}
444
445Preallocates memory for a given number of array elements. It is worth calling
446when the number of items which are going to be added to the array is known in
447advance because it will save unneeded memory reallocation. If the array already
448has enough memory for the given number of items, nothing happens.
449
450\membersection{wxArray::Clear}\label{wxarrayclear}
451
452\func{void}{Clear}{\void}
453
454This function does the same as \helpref{Empty()}{wxarrayempty} and additionally
455frees the memory allocated to the array.
456
457\membersection{wxArray::Count}\label{wxarraycount}
458
459\constfunc{size\_t}{Count}{\void}
460
461Same as \helpref{GetCount()}{wxarraygetcount}. This function is deprecated -
462it exists only for compatibility.
463
464\membersection{wxObjArray::Detach}\label{wxobjarraydetach}
465
466\func{T *}{Detach}{\param{size\_t }{index}}
467
468Removes the element from the array, but, unlike,
469\helpref{Remove()}{wxarrayremove} doesn't delete it. The function returns the
470pointer to the removed element.
471
472\membersection{wxArray::Empty}\label{wxarrayempty}
473
474\func{void}{Empty}{\void}
475
476Empties the array. For wxObjArray classes, this destroys all of the array
477elements. For wxArray and wxSortedArray this does nothing except marking the
478array of being empty - this function does not free the allocated memory, use
479\helpref{Clear()}{wxarrayclear} for this.
480
481\membersection{wxArray::GetCount}\label{wxarraygetcount}
482
483\constfunc{size\_t}{GetCount}{\void}
484
485Return the number of items in the array.
486
487\membersection{wxArray::Index}\label{wxarrayindex}
488
489\func{int}{Index}{\param{T\& }{item}, \param{bool }{searchFromEnd = false}}
490
491\func{int}{Index}{\param{T\& }{item}}
492
493The first version of the function is for wxArray and wxObjArray, the second is
494for wxSortedArray only.
495
496Searches the element in the array, starting from either beginning or the end
497depending on the value of {\it searchFromEnd} parameter. wxNOT\_FOUND is
498returned if the element is not found, otherwise the index of the element is
499returned.
500
501Linear search is used for the wxArray and wxObjArray classes but binary search
502in the sorted array is used for wxSortedArray (this is why searchFromEnd
503parameter doesn't make sense for it).
504
505{\bf NB:} even for wxObjArray classes, the operator==() of the elements in the
506array is {\bf not} used by this function. It searches exactly the given
507element in the array and so will only succeed if this element had been
508previously added to the array, but fail even if another, identical, element is
509in the array.
510
511\membersection{wxArray::Insert}\label{wxarrayinsert}
512
513\func{void}{Insert}{\param{T }{item}, \param{size\_t }{n}, \param{size\_t }{copies = $1$}}
514
515\func{void}{Insert}{\param{T *}{item}, \param{size\_t }{n}}
516
517\func{void}{Insert}{\param{T \&}{item}, \param{size\_t }{n}, \param{size\_t }{copies = $1$}}
518
519Insert the given number of {\it copies} of the {\it item} into the array before
520the existing item {\it n} - thus, {\it Insert(something, 0u)} will insert an
521item in such way that it will become the first array element.
522
523Please see \helpref{Add()}{wxarrayadd} for explanation of the differences
524between the overloaded versions of this function.
525
526\membersection{wxArray::IsEmpty}\label{wxarrayisempty}
527
528\constfunc{bool}{IsEmpty}{\void}
529
530Returns true if the array is empty, false otherwise.
531
532\membersection{wxArray::Item}\label{wxarrayitem}
533
534\constfunc{T\&}{Item}{\param{size\_t }{index}}
535
536Returns the item at the given position in the array. If {\it index} is out of
537bounds, an assert failure is raised in the debug builds but nothing special is
538done in the release build.
539
540The returned value is of type "reference to the array element type" for all of
541the array classes.
542
543\membersection{wxArray::Last}\label{wxarraylast}
544
545\constfunc{T\&}{Last}{\void}
546
547Returns the last element in the array, i.e. is the same as Item(GetCount() - 1).
548An assert failure is raised in the debug mode if the array is empty.
549
550The returned value is of type "reference to the array element type" for all of
551the array classes.
552
553\membersection{wxArray::Remove}\label{wxarrayremove}
554
555\func{\void}{Remove}{\param{T }{item}}
556
557Removes an element from the array by value: the first item of the
558array equal to {\it item} is removed, an assert failure will result from an
559attempt to remove an item which doesn't exist in the array.
560
561When an element is removed from wxObjArray it is deleted by the array - use
562\helpref{Detach()}{wxobjarraydetach} if you don't want this to happen. On the
563other hand, when an object is removed from a wxArray nothing happens - you
564should delete it manually if required:
565
566\begin{verbatim}
567T *item = array[n];
568delete item;
569array.Remove(n)
570\end{verbatim}
571
572See also \helpref{WX\_CLEAR\_ARRAY}{wxcleararray} macro which deletes all
573elements of a wxArray (supposed to contain pointers).
574
575\membersection{wxArray::RemoveAt}\label{wxarrayremoveat}
576
577\func{\void}{RemoveAt}{\param{size\_t }{index}, \param{size\_t }{count = $1$}}
578
579Removes {\it count} elements starting at {\it index} from the array. When an
580element is removed from wxObjArray it is deleted by the array - use
581\helpref{Detach()}{wxobjarraydetach} if you don't want this to happen. On
582the other hand, when an object is removed from a wxArray nothing happens -
583you should delete it manually if required:
584
585\begin{verbatim}
586T *item = array[n];
587delete item;
588array.RemoveAt(n)
589\end{verbatim}
590
591See also \helpref{WX\_CLEAR\_ARRAY}{wxcleararray} macro which deletes all
592elements of a wxArray (supposed to contain pointers).
593
594\membersection{wxArray::SetCount}\label{wxarraysetcount}
595
596\func{void}{SetCount}{\param{size\_t }{count}, \param{T }{defval = T($0$)}}
597
598This function ensures that the number of array elements is at least
599{\it count}. If the array has already {\it count} or mroe items, nothing is
600done. Otherwise, {\tt count - GetCount()} elements are added and initialized to
601the value {\it defval}.
602
603\wxheading{See also}
604
605\helpref{GetCount}{wxarraygetcount}
606
607\membersection{wxArray::Shrink}\label{wxarrayshrink}
608
609\func{void}{Shrink}{\void}
610
611Frees all memory unused by the array. If the program knows that no new items
612will be added to the array it may call Shrink() to reduce its memory usage.
613However, if a new item is added to the array, some extra memory will be
614allocated again.
615
616\membersection{wxArray::Sort}\label{wxarraysort}
617
618\func{void}{Sort}{\param{CMPFUNC<T> }{compareFunction}}
619
620The notation CMPFUNC<T> should be read as if we had the following declaration:
621
622\begin{verbatim}
623template int CMPFUNC(T *first, T *second);
624\end{verbatim}
625
626where {\it T} is the type of the array elements. I.e. it is a function returning
627{\it int} which is passed two arguments of type {\it T *}.
628
629Sorts the array using the specified compare function: this function should
630return a negative, zero or positive value according to whether the first element
631passed to it is less than, equal to or greater than the second one.
632
633wxSortedArray doesn't have this function because it is always sorted.
634